docs: add ccamara as a contributor for doc (#236)

Co-authored-by: allcontributors[bot] <46447321+allcontributors[bot]@users.noreply.github.com>

.all-contributorsrc

@@ -396,7 +396,8 @@
       "avatar_url": "https://avatars.githubusercontent.com/u/706549?v=4",
       "profile": "http://carloscamara.es/en",
       "contributions": [
-        "maintenance"
+        "maintenance",
+        "doc"
       ]
     }
   ],

README.md

@@ -107,7 +107,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     </tr>
     <tr>
       <td align="center" valign="top" width="14.28%"><a href="https://ellakaye.co.uk"><img src="https://avatars.githubusercontent.com/u/7222491?v=4?s=100" width="100px;" alt="Ella Kaye"/><br /><sub><b>Ella Kaye</b></sub></a><br /><a href="https://github.com/r-devel/rdevguide/commits?author=EllaKaye" title="Code">💻</a> <a href="#infra-EllaKaye" title="Infrastructure (Hosting, Build-Tools, etc)">🚇</a></td>
-      <td align="center" valign="top" width="14.28%"><a href="http://carloscamara.es/en"><img src="https://avatars.githubusercontent.com/u/706549?v=4?s=100" width="100px;" alt="Carlos Cámara"/><br /><sub><b>Carlos Cámara</b></sub></a><br /><a href="#maintenance-ccamara" title="Maintenance">🚧</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="http://carloscamara.es/en"><img src="https://avatars.githubusercontent.com/u/706549?v=4?s=100" width="100px;" alt="Carlos Cámara"/><br /><sub><b>Carlos Cámara</b></sub></a><br /><a href="#maintenance-ccamara" title="Maintenance">🚧</a> <a href="https://github.com/r-devel/rdevguide/commits?author=ccamara" title="Documentation">📖</a></td>
     </tr>
   </tbody>
 </table>